Water blended fuel composition

ABSTRACT

This invention relates to a water blended fuel composition made by combining: (i) a normally liquid hydrocarbon fuel; (ii) water; and (iii) a nitrogen-free surfactant. The fuel composition may be used as the fuel for use in an open flame burning apparatus or in an internal combustion engine.

TECHNICAL FIELD

[0001] This invention relates to a water blended fuel composition. Moreparticularly, this invention relates to a water blended fuel compositioncomprising a normally liquid hydrocarbon fuel, water, and anitrogen-free surfactant. These fuel compositions may be used inopen-flame burners and internal combustion engines.

BACKGROUND OF THE INVENTION

[0002] A major objective of using a water blended fuel is to lower NOx(nitrogen oxides) emissions. In internal combustion engines, such astypical diesel engines for on-road vehicles, combustion temperaturesusually approach about 2000° C. Under these conditions, the majority ofthe NOx produced is from oxidized atmospheric nitrogen that is pulledinto the engine's manifold. On the other hand, combustion occurs atlower temperatures in open-flame burners such as in industrial boilers.At such lower temperatures, lower amounts of atmospheric N₂ are oxidizedand most of the NOx produced by such burners results from nitrogenintroduced via the fuel and fuel additives.

[0003] Current commercial water blended fuel additive formulations,which are formulated for use in internal combustion engines contain onthe order of 1000-1500 ppm nitrogen. The base fuel typically introducesabout 100 to about 300 ppm nitrogen with the remainder coming from theadditives. A significant portion of the nitrogen contributed to thesefuels comes from surfactants which are used to stabilize the waterblended fuels.

[0004] The problem, therefore, is to provide nitrogen-free surfactantsfor use in applications where nitrogen level is an issue, such asindustrial boilers. Low nitrogen content may also become a factor ininternal combustion engines as NOx emission levels are expected to besignificantly lower by 2007.

[0005] This invention provides a solution to this problem by providing awater blended fuel composition containing a nitrogen-free surfactant.These fuels may be used advantageously in open-flame burners such asindustrial boilers. These fuels are also useful in internal combustionengines.

SUMMARY OF THE INVENTION

[0006] This invention relates to a water blended fuel composition madeby combining:

[0007] (i) a normally liquid hydrocarbon fuel;

[0008] (ii) water; and

[0009] (iii) a nitrogen-free surfactant comprising:

[0010] (iii)(a) a hydrocarbyl substituted carboxylic acid, or a reactionproduct of the hydrocarbyl substituted carboxylic acid or a reactiveequivalent of such acid with an alcohol, the hydrocarbyl substituent ofthe acid or reactive equivalent thereof containing at least about 30carbon atoms; and

[0011] (iii)(b) at least one compound represented by one or more of theformulae:

RO(R′O)_(n)R′″  (iii-b-1)

 RCOO(R′O)_(n)R′″  (iii-b-3)

[0012] wherein each R is independently hydrogen or a hydrocarbyl groupof up to about 60 carbon atoms; each R′ and R″ is independently analkylene group of 1 to about 20 carbon atoms; each R′″ is independentlyhydrogen, or an acyl or hydrocarbyl group of up to about 30 carbonatoms; n is a number in the range of zero to about 50; and x, y and zare independently numbers in the range of zero to about 50 with thetotal for x, y and z being at least 1.

[0013] In one embodiment, the water blended fuel composition furthercomprises an optional acid component, the acid having a pKa of up toabout 6.

[0014] In one embodiment, the water blended fuel composition is suitablefor use as a fuel for an open flame burning apparatus, and in oneembodiment as a fuel for an internal combustion engine.

DETAILED DESCRIPTION OF THE INVENTION

[0015] The term “hydrocarbyl” and “hydrocarbon,” when referring togroups attached to the remainder of a molecule, refer to groups having apurely hydrocarbon or predominantly hydrocarbon character within thecontext of this invention. Such groups include the following:

[0016] (1) Purely hydrocarbon groups; that is, aliphatic, alicyclic,aromatic, aliphatic- and alicyclic-substituted aromatic,aromatic-substituted aliphatic and alicyclic groups, and the like, aswell as cyclic groups wherein the ring is completed through anotherportion of the molecule (that is, any two indicated substituents maytogether form an alicyclic group). Examples include methyl, octyl,cyclohexyl, phenyl, etc.

[0017] (2) Substituted hydrocarbon groups; that is, groups containingnon-hydrocarbon substituents which do not alter the predominantlyhydrocarbon character of the group. Examples include hydroxy, alkoxy,acyl, etc.

[0018] (3) Hetero groups; that is, groups which, while predominantlyhydrocarbon in character, contain atoms other than carbon in a chain orring otherwise composed of carbon atoms. Examples include oxygen andsulfur.

[0019] In general, no more than about three substituents or heteroatoms, and in one embodiment no more than one, will be present for each10 carbon atoms in the hydrocarbyl or hydrocarbon group.

[0020] The term “lower” as used herein in conjunction with terms such ashydrocarbon, alkyl, alkenyl, alkoxy, and the like, is intended todescribe such groups which contain a total of up to 7 carbon atoms.

[0021] The term “oil-soluble” refers to a material that is soluble inmineral oil or hydrocarbon fuel to the extent of at least about 0.5 gramper liter at 25° C.

[0022] The term “water-soluble” refers to materials that are soluble inwater to the extent of at least 0.5 gram per 100 milliliters of water at25° C.

[0023] The Water Blended Fuel Composition

[0024] The water blended fuel composition may be in the form of awater-in-oil emulsion or a micro-emulsion. Throughout the specificationand in the appended claims the term “oil” (as in water-in-oil emulsion)is sometimes used to refer to the normally liquid hydrocarbon fuel phaseof the water blended fuel composition.

[0025] The water blended fuel composition contains (i) a normally liquidhydrocarbon fuel, (ii) water, and (iii) a nitrogen-free surfactant.These fuels may also include as optional ingredients one or more acidshaving a pKa of up to about 6, cetane improvers, non-metallic combustionmodifiers, metallic combustion modifiers, water-soluble salts,antifreeze agents, organic solvents, as well as other fuel additivesknown in the art.

[0026] Although the surfactant (iii) used in the inventive water blendedfuel composition is a nitrogen-free surfactant and with these fuelcompositions it is desirable to reduce or eliminate the use ofnitrogen-containing ingredients, it is permissible to include nitrogencontaining ingredients (e.g., various cetane improvers, non-metalliccombustion modifiers, water-soluble salts such as ammonium nitrate, andthe like) in various embodiments of the inventive fuel compositions toprovide desirable performance attributes to such fuel compositions.

[0027] The water blended fuel composition may be characterized by acontinuous oil or fuel phase and a discontinuous or dispersed aqueousphase. These emulsions may be characterized as water-in-oil emulsions ormicro emulsions. The term “micro emulsion” generally refers to emulsionswherein the dispersed phase is characterized by droplets having a meandiameter of up to about 0.1 micron. The dispersed aqueous phase for theinventive water blended fuel composition may be comprised of aqueousdroplets having a mean diameter of about up to about 50 microns, and inone embodiment about 0.01 to about 50 microns, and in one embodimentabout 0.01 to about 30 microns, and in one embodiment about 0.01 toabout 20 microns, and in one embodiment about 0.01 to about 10 microns,and in one embodiment, 0.01 to about 5 microns, and in one embodimentabout 0.05 to about 2 microns, and in one embodiment about 0.05 to about1 micron, and in one embodiment about 0.05 to about 0.8 micron, and inone embodiment about 0.1 to about 1.0 micron, and in one embodimentabout 0.5 to about 1.0 micron.

[0028] The Normally Liquid Hydrocarbon Fuel (i)

[0029] The normally liquid hydrocarbon fuel may be a hydrocarbonaceouspetroleum distillate fuel such as motor gasoline as defined by ASTMSpecification D439 or diesel fuel or fuel oil as defined by ASTMSpecification D396. The normally liquid hydrocarbon fuel may be abiodegradable fuel, a biodiesel fuel, or a mixture thereof. The fuel maybe a residual fuel. Normally liquid hydrocarbon fuels comprisingnon-hydrocarbonaceous materials such as alcohols, ethers, and the like(e.g., methanol, ethanol, diethyl ether, methyl ethyl ether) are alsowithin the scope of this invention as are liquid fuels derived fromvegetable or mineral sources such as corn, alfalfa, rapeseed, soybeans,shale and coal. The fuel may be derived from Fischer-Tropsch synthesizedhydrocarbons. Normally liquid hydrocarbon fuels which are mixtures ofone or more hydrocarbonaceous fuels and one or morenon-hydrocarbonaceous materials are also contemplated. Examples of suchmixtures are combinations of gasoline and ethanol, and diesel fuel andether.

[0030] The gasoline that is useful may be a mixture of hydrocarbonshaving an ASTM distillation range from about 60° C. at the 10%distillation point to about 205° C. at the 90% distillation point.

[0031] The diesel fuel may be any diesel fuel. The diesel fuel may havea 90% point distillation temperature in the range of about 300° C. toabout 390° C., and in one embodiment about 330° C. to about 350° C. Theviscosity for the diesel fuel may range from about 1 to about 24centistokes at 40° C. The diesel fuel may be classified as any of GradeNos. 1-D, 2-D or 4-D as specified in ASTM D975. These diesel fuels maycontain alcohols and esters. In one embodiment the diesel fuel has asulfur content of up to about 0.05% by weight (low-sulfur diesel fuel)as determined by the test method specified in ASTM D2622-87.

[0032] The fuel oil may be a Grade No. 1, No. 1 low sulfur, No. 2, No. 2low sulfur, No. 4, No. 4 light, No. 5 light, No. 5 heavy, or No. 6 asdefined by ASTM Specification D396-01. The fuel oil may be a Grade No. 3fuel oil. The fuel oil may be a residual fuel that is heavier than No.6. The fuel may comprise bitumen.

[0033] The normally liquid hydrocarbon fuel may be present in the waterblended fuel composition at a concentration of about 50% to about 99.5%by weight, and in one embodiment about 55 to about 99% by weight, and inone embodiment about 60 to about 98% by weight, and in one embodimentabout 65 to about 95% by weight, and in one embodiment about 75 to about95% by weight.

[0034] The Water (ii)

[0035] The water may be taken from any convenient source. In oneembodiment, the water is deionized. In one embodiment, the water is notdeionized. In one embodiment, the water is purified using reverseosmosis or distillation. The water may be in the form of waste watersuch as condensed steam from a boiler.

[0036] The water may be present in the water blended fuel composition ata concentration of about 0.5 to about 50% by weight, and in oneembodiment about 1 to about 45% by weight, and in one embodiment about 2to about 40% by weight, and in one embodiment about 5 to about 35% byweight, and in one embodiment about 5 to about 25% by weight.

[0037] The Nitrogen-Free Surfactant (iii)

[0038] The nitrogen-free surfactant (iii) may function as an emulsifierand may be referred to as an emulsifier. The surfactant (iii) comprisesthe combination of surfactant components (iii)(a) and (iii)(b) referredto above and discussed below.

[0039] The above-indicated combination of surfactant components providesfor the formation of stable emulsions. These emulsions may becharacterized by a shelf life of at least about 1 day, and in oneembodiment at least about 5 days, and in one embodiment at least about10 days, and in one embodiment at least about 20 days, and in oneembodiment at least about 50 days, and in one embodiment at least about90 days. While not wishing to be bound by theory it is believed thatsurfactant component (iii)(a) provides the water blended fuelcomposition with long-term stability while surfactant component (iii)(b)enables formation of the emulsion rapidly with a small particle size forthe aqueous droplets.

[0040] The term “nitrogen-free” does not exclude the possibility ofnitrogen being present in the surfactant (iii) at contaminate levels.Typical contaminate levels may be up to about 100 ppm, and in oneembodiment up to about 200 ppm, and in one embodiment up to about 300ppm, and in one embodiment up to about 400 ppm, and in one embodiment upto about 500 ppm, and in one embodiment up to about 700 ppm, and in oneembodiment up to about 1000 ppm.

[0041] The concentration of the surfactant (iii)(a) in the water blendedfuel composition may range from about 0.05 to about 5% by weight, and inone embodiment about 0.1 to about 3% by weight, and in one embodimentabout 0.1 to about 2% by weight.

[0042] The concentration of surfactant (iii)(b) in the water blendedfuel composition may range from about 0.05 to about 5% by weight, and inone embodiment about 0.1 to about 3 percent by weight, and in oneembodiment about 0.1 to about 2% by weight.

[0043] The weight ratio of surfactant (iii)(a) to surfactant (iii)(b)may range from about 1:9 to about 9:1, and in one embodiment about 3:1to about 1:3, and in one embodiment about 2:1 to about 1:2.5, and in oneembodiment about 1:1.5 to about 1:2.5, and in one embodiment about 1:2.

[0044] Surfactant Component (iii)(a)

[0045] The surfactant component (iii)(a) may be a hydrocarbylsubstituted carboxylic acid, or a reaction product of the hydrocarbylsubstituted carboxylic acid or a reactive equivalent thereof with analcohol. The carboxylic acids may be monobasic or polybasic. Thepolybasic acids include dicarboxylic acids, although tricarboxylic andtetracarboxylic acids may be used. The reactive equivalents may be acidhalides, (e.g., chlorides), anhydrides or esters, including partialesters, and the like.

[0046] The hydrocarbyl substituted carboxylic acid or reactiveequivalent may be made by reacting one or more alpha, beta olefinicallyunsaturated carboxylic acid reagents containing 2 to about 20 carbonatoms, exclusive of the carboxyl groups, with one or more olefinpolymers. The olefin polymers may contain about 30 to about 500 carbonatoms, and in one embodiment about 50 to about 500 carbon atoms.

[0047] The alpha-beta olefinically unsaturated carboxylic acid reagentsmay be either monobasic or polybasic in nature. Exemplary of themonobasic alpha-beta olefinically unsaturated carboxylic acid reagentsinclude the carboxylic acids corresponding to the formula

[0048] wherein R is hydrogen, or a saturated aliphatic or alicyclic,aryl, alkylaryl or heterocyclic group, and R¹ is hydrogen or a loweralkyl group. R may be a lower alkyl group. The total number of carbonatoms in R and R¹ typically does not exceed about 18 carbon atoms.Examples include acrylic acid; methacrylic acid; cinnamic acid; crotonicacid; 3-phenyl propenoic acid; alpha, and beta-decenoic acid. Thepolybasic acid reagents may be dicarboxylic, although tri- andtetracarboxylic acids can be used. Examples include maleic acid, fumaricacid, mesaconic acid, itaconic acid and citraconic acid. Reactiveequivalents include the anhydride, halide or ester functionalderivatives of the foregoing acids. A useful reactive equivalent ismaleic anhydride.

[0049] The olefin monomers from which the olefin polymers may be derivedare polymerizable olefin monomers characterized by having one or moreethylenic unsaturated groups. They can be monoolefinic monomers such asethylene, propylene, butene-1, isobutene and octene-1, or polyolefinicmonomers (usually di-olefinic monomers such as butadiene-1,3 andisoprene). Usually these monomers are terminal olefins, that is, olefinscharacterized by the presence of the group >C═CH₂. However, certaininternal olefins can also serve as monomers (these are sometimesreferred to as medial olefins). When such medial olefin monomers areused, they normally are employed in combination with terminal olefins toproduce olefin polymers that are interpolymers. The olefin polymers mayinclude aromatic groups and alicyclic groups. These include polymersderived from both 1,3-dienes and styrenes, such as butadiene-1,3 andstyrene or para-(tertiary butyl) styrene; also included are partiallyhydrogenated polymers derived from the foregoing.

[0050] Generally the olefin polymers are homo- or interpolymers ofterminal hydrocarbon olefins of about 2 to about 30 carbon atoms, and inone embodiment about 2 to about 16 carbon atoms, and in one embodimentabout 2 to about 6 carbon atoms, and in one embodiment 2 to about 4carbon atoms.

[0051] The olefin polymer may be a polyisobutene, polypropylene,polyethylene, a copolymer derived from isobutene and butadiene, or acopolymer derived from isobutene and isoprene.

[0052] In one embodiment, the olefin polymers are polyisobutenes (orpolyisobutylenes) such as those obtained by polymerization of a C₄refinery stream having a butene content of about 35 to about 75% byweight and an isobutene content of about 30 to about 60% by weight inthe presence of a Lewis acid catalyst such as aluminum chloride or borontrifluoride. These polyisobutenes generally contain predominantly (thatis, greater than about 50 percent of the total repeat units) isobutenerepeat units.

[0053] The olefin polymer may be a polyisobutene having a highmethylvinylidene isomer content. These include the polyisobuteneswherein at least about 50% by weight, and in one embodiment at leastabout 70% by weight, of the polyisobutenes have methylvinylidene endgroups. Suitable polyisobutenes having such high methylvinylidene isomercontents include those prepared using boron trifluoride catalysts.

[0054] The hydrocarbyl substituted carboxylic acid or reactiveequivalent may be a hydrocarbyl (e.g., polyisobutene) substitutedsuccinic acid or anhydride wherein the hydrocarbyl substituent has fromabout 30 to about 500 carbon atoms, and in one embodiment from about 50to about 500 carbon atoms. The hydrocarbyl substituent may have a numberaverage molecular weight of about 750 to about 3000, and in oneembodiment about 900 to about 2000. In one embodiment, the numberaverage molecular weight is from about 750 to about 1500, and in oneembodiment it is from about 1500 to about 3000.

[0055] In one embodiment, the hydrocarbyl-substituted succinic acids orreactive equivalents thereof are characterized by the presence withintheir structure of an average of at least about 1.3 succinic groups, andin one embodiment from about 1.5 to about 2.5, and in one embodimentform about 1.7 to about 2.1 succinic groups for each equivalent weightof the hydrocarbyl substituent. The ratio of succinic groups toequivalent of substituent groups present in the hydrocarbyl substitutedsuccinic acid or reactive equivalent (also called the “succinationratio”) may be determined by one skilled in the art using conventionaltechniques (e.g., saponification or acid numbers). This is described inU.S. Pat. No. 4,234,435, which is incorporated herein by reference.

[0056] The conditions for reacting the alpha, beta olefinicallyunsaturated carboxylic acid reagent with the olefin polymer are known tothose in the art. Examples of patents describing various procedures forpreparing useful hydrocarbyl substituted carboxylic acids or reactiveequivalents thereof include U.S. Pat. Nos. 3,215,707; 3,219,666;3,231,587; 3,912,764; 4,110,349; and 4,234,435; and U.K. Patent1,440,219. The disclosures of these patents are hereby incorporated byreference.

[0057] The alcohol which may be reacted with the hydrocarbyl substitutedcarboxylic acid or reactive equivalent to form surfactant component(iii)(a) may be a mono- or a polyhydric hydrocarbon-based alcohol suchas methanol, ethanol, the propanols, butanols, pentanols, hexanols,heptanols, octanols, decanols, and the like. Also included are fattyalcohols and mixtures thereof, including saturated alcohols such aslauryl, myristyl, cetyl, stearyl and behenyl alcohols, and unsaturatedalcohols such as palmitoleyl, oleyl and eicosenyl. Higher syntheticmonohydric alcohols of the type formed by the Oxo process (e.g.,2-ethylhexanol), by the aldol condensation, or byorganoaluminum-catalyzed oligomerixation of alpha-olefins (e.g.,ethylene), followed by oxidation, may be used. Alicyclic analogs of theabove-described alcohols may be used; examples include cyclopentanol,cyclohexanol, cyclododecanol, and the like.

[0058] The polyhydroxy compounds that may be used include ethylene,propylene, butylene, pentylene, hexylene and heptylene glycols; tri-,tetra-, penta-, hexa- and heptamethylene glycols andhydrocarbon-substituted analogs thereof (e.g., 2-ethyl-1,3-trimethyleneglycol, neopentyl glycol, etc.), as well as polyoxyalkylene compoundssuch as diethylene and higher polyethylene glycols, tripropylene glycol,dibutylene glycol, dipentylene glycol, dihexylene glycol and diheptyleneglycol, and their monoethers. A glycol that may be used is 1,2-propanediol.

[0059] Phenol, naphthols, substituted phenols (e.g., the cresols), anddihydroxyaromatic compounds (e.g., resorcinol, hydroquinone), as well asa benzyl alcohol and similar di-hydroxy compounds wherein the secondhydroxy group is directly bonded to an aromatic carbon (e.g., 3-HOΦCH₂OHwherein Φ is a divalent benzene ring) may be used. Sugar alcohols of thegeneral formula HOCH₂ (CHOH)₁₋₅ CH₂OH such as glycerol, sorbitol,mannitol, and the like, and their partially esterified derivatives maybe used. Oligomers of such sugar alcohols, including diglycerol,triglycerol, hexaglycerol, and the like, and their partially esterfiedderivatives may be used. Methylol polyols such as pentaerythritol andits oligomers (di- and tripentaerythritol, etc.), trimethylolethane,trimethylolpropane, and the like may be used.

[0060] The surfactant component (iii)(a) may be in the form of an acid,an ester, or a mixture thereof. The acid may be formed by reacting ahydrocarbyl substituted carboxylic acid reactive equivalent with waterto provide the desired acid. For example, hydrocarbyl (e.g.,polyisobutene) substituted succinic anhydride may be reacted with waterto form hydrocarbyl substituted succinic acid. The reaction between thehydrocarbyl substituted carboxylic acid or reactive equivalent thereofand the alcohol to form an ester may be carried out under suitable esterforming reaction conditions. Typically, the reaction is carried out at atemperature in the range of from about 50° C. to about 250° C.;optionally in the presence of a normally liquid, substantially inertorganic liquid solvent/diluent, until the desired product has formed. Inone embodiment, the hydrocarbyl substituted carboxylic acid or reactiveequivalent thereof and the alcohol are reacted in amounts sufficient toprovide from about 0.3 to about 3 equivalents of the acid or reactiveequivalent thereof per equivalent of alcohol. In one embodiment, thisratio is from about 0.5:1 to about 2:1.

[0061] The number of equivalents of the hydrocarbyl substitutedcarboxylic acid or reactive equivalent thereof depends on the totalnumber of carboxylic functions present which are capable of reactingwith the alcohol. For example, there would be two equivalents in ananhydride derived from the reaction of one mole of olefin polymer andone mole of maleic anhydride.

[0062] The weight of an equivalent of an alcohol is its molecular weightdivided by the total number of hydroxyl groups present in the molecule.Thus, the weight of an equivalent of ethylene glycol is one-half itsmolecular weight.

[0063] Surfactant Component (iii)(b)

[0064] The surfactant component (iii)(b) may be at least one compoundrepresented by one or more of the formulae:

RO(R′O)_(n)R′″  (iii-b-1)

 RCOO(R′O)_(n)R′″  (iii-b-3)

[0065] wherein each R is independently hydrogen or a hydrocarbyl groupof up to about 60 carbon atoms; each R′ and R″ is independently analkylene group of 1 to about 20 carbon atoms; each R′″ is independentlyhydrogen, or an acyl or hydrocarbyl group of up to about 30 carbonatoms; n is a number in the range of zero to about 50; and x, y and zare independently numbers in the range of zero to about 50 with thetotal for x, y and z being at least 1. In the above formulae, R may be ahydrocarbyl group of about 6 to about 60 carbon atoms, and in oneembodiment abut 6 to about 45 carbon atoms, and in one embodiment about6 to about 30 carbon atoms, and in one embodiment about 14 to about 30carbon atoms. In one embodiment, R may be a hydrocarbyl group of about 9to about 11 carbon atoms. R′ and R″ may be independently alkylene groupsof about 1 to about 6 carbon atoms, and in one embodiment about 1 toabout 4 carbon atoms. In one embodiment, R′ is an alkylene groupcontaining about 2 to about 3 carbon atoms, and in one embodiment about2 carbon atoms. In one embodiment, R″ is an alkylene group containing 1carbon atom. R′″ may be an acyl or hydrocarbyl group of 1 to about 30carbon atoms, and in one embodiment 1 to about 24 carbon atoms, and inone embodiment 1 to about 18 carbon atoms, and in one embodiment 1 toabout 12 carbon atoms, and in one embodiment 1 to about 6 carbon atoms.n may be a number in the range of 1 to about 50, and in one embodiment 1to about 30, and in one embodiment 1 to about 20, and in one embodiment1 to about 12, and in one embodiment about 4 to about 10, and in oneembodiment about 5 to about 10, and in one embodiment about 5 to about8, and in one embodiment about 5 or about 6. x, y and z may beindependently numbers in the range of zero to about 50, and in oneembodiment zero to about 30, and in one embodiment zero to about 10;with the total of x, y and z being at least 1, and in one embodiment inthe range of 1 to about 50, and in one embodiment 10 to about 40, and inone embodiment 20 to about 30, and in one embodiment about 25.

[0066] Examples of compounds represented by formula (iii-b-1) that maybe used include: C₉-C₁₁ alkoxy poly (ethoxy)₈ alcohol; C₁₂-C₁₅ alkoxypoly (isopropoxy)₂₂-₂₆ alcohol; oleyl alcohol pentaethoxylate; and thelike.

[0067] Examples of compounds represented by formula (iii-b-2) that maybe used include diglycerol monooleate, diglycerol monosteaate,polyglycerol monooleate, and the like.

[0068] Examples of compounds represented by formula (iii-b-3) that maybe used include polyethylene glycol (Mn=200) distearate, polyethyleneglycol (Mn=400) distearate, polyethylene glycol (Mn=200) dioleate,polyethylene glycol (Mn=400) soya bean oil ester, and the like.

[0069] Examples of compounds represented by formula (iii-b-4) that maybe used include glycerol monooleate, diglycerol dioleate, diglyceroldistearate, polyglycerol dioleate, and the like.

[0070] Examples of compounds represented by formula (iii-b-5) that maybe used include sorbitan monooleate, sorbitan monoisostearate, sorbitansesquioleate, and sorbitan trioleate, and the like.

[0071] Examples of compounds represented by formula (iii-b-6) that maybe used include polyethoxy glycerol trioleate wherein the compoundcontains 25 ethoxy groups.

[0072] In one embodiment, the surfactant (iii)(b) is an alkoxypolyethoxy alcohol wherein the alkoxy group contains about 14 to about30 carbon atoms and the polyethoxy group contains up to about 10 ethoxygroups, and in one embodiment about 5 to about 10 ethoxy groups, and inone embodiment about 5 or 6 ethoxy groups.

[0073] In one embodiment, the surfactant (iii)(b) is an alkoxypolyethoxy alcohol wherein the alkoxy group contains about 9 to about 11carbon atoms and the polyethoxy group contains about 8 ethoxy groups.

[0074] Optional Acid Component

[0075] An optional acid component that may be used in the inventive fuelcomposition comprises one or more acids having a pKa of up to about 6,and in one embodiment up to about 5, and in one embodiment up to about4, and in one embodiment from about 0 to about 4, and in one embodimentabout 1 to about 3.5, and in one embodiment about 1.5 to about 3. Thisacid component may be a carboxylic acid. Examples of the carboxylicacids that may be used include those represented by the formula

(X)_(m)R(COOH)_(n)  (OAC-1)

[0076] wherein in formula (OAC-1), X is an electron withdrawing group, Ris hydrogen or a hydrocarbon group, m is a number in the range of zeroto about 10, and n is a number that is at least 1. Examples of theelectron withdrawing groups X that may be used include hydroxyl groups,alkoxy groups, acyl groups, carboalkoxy groups, keto groups, oxo group,aromatic rings, or a combination of two or more thereof. R may be analiphatic, alicyclic, aromatic, aliphatic- or alicyclic-substitutedaromatic, aromatic-substituted aliphatic or alicyclic group. R maycontain 1 to about 18 carbon atoms, and in one embodiment 1 to about 10carbon atoms, and in one embodiment 1 to about 6 carbon atoms. m may bea number in the range of 1 to about 10, and in one embodiment 1 to about6, and in one embodiment 1 to about 4. n may be a number in the range of1 to about 10, and in one embodiment 1 to about 8, and in one embodiment1 to about 4, and in one embodiment 1 to about 2. When n is 2 or more,the additional COOH groups may serve as electron withdrawing groups.Examples of the acids that may be used include: Acid pKa Formic acid3.75 Acetylenedicarboxylic acid 1.75 Benzenehexacarboxylic acid 0.68Benzenepentacarboxylic acid 1.80 Benzenetetracarboxylic acid 1.92Benzenetricarboxylic acid 2.12 2-Butyn-1,4-dioic acid 1.75 2-Butynoicacid 2.62 Citraconic acid 2.29 Cyclopropane-1,1-dicarboxylic acid 1.822,6-Dihydroxybenzoic acid 1.30 Dihydroxymaleic acid 1.10 Dihydroxymalicacid 1.92 Dihydroxytatric acid 1.95 alpha, alpha-Dimethyloxaloaceticacid 1.77 Dipropylmalonic acid 2.04 Ethylene oxide dicarboxylic acid1.93 Hydroxyaspartic acid 1.91 Maleic acid 1.91 2-Oxobutanoic acid 2.50Triethylsuccinic acid 2.74 Citric acid 3.13 Tartaric Acid 2.98 Glyoxylicacid 3.34 Oxalic acid 1.23 Lactic acid 3.08 Oxomalonic acid (mesoxalicacid)

[0077] When used, this acid component may function as an ionizing agent.The concentration of this acid component in the water blended fuelcomposition may range up to about 5 percent by weight, and in oneembodiment from about 0.001 to about 3 percent by weight, and in oneembodiment about 0.01 to about 1 percent by weight.

[0078] Cetane Improvers

[0079] The cetane improvers include peroxides, percarbonates, nitrocompounds, nitrates, nitrites, nitrocarbamates, and the like. Examplesinclude nitropropane, 2-nitro-2-methyl-1 -butanol, and the like. Alsoincluded are nitrate esters of substituted or unsubstituted aliphatic orcycloaliphatic alcohols which may be monohydric or polyhydric. Theseinclude substituted and unsubstituted alkyl or cycloalkyl nitrateshaving up to about 10 carbon atoms. The alkyl group may be either linearor branched. Examples include methyl nitrate, butyl nitrate,2-ethylhexyl nitrate, and the like.

[0080] The concentration of the cetane improver in the water blendedfuel composition may be at a level of up to about 10% by weight, and inone embodiment about 0.05 to about 5% by weight.

[0081] Non-Metallic Combustion Modifiers

[0082] The non-metallic combustion modifiers include strained ringcompounds, nitro compounds, nitrates, and certain hydroxyamines.Strained ring compounds are compounds containing cyclic rings of about 3to about 5 atoms, and in one embodiment about 3 to about 4 atoms. Thestrained rings are typically saturated, but the about 3 and about 4membered rings may contain olefinic unsaturation. The strained ringcompounds may be monocyclic or polycyclic compounds. The polycycliccompounds may have fused ring systems, and/or ring systems connecteddirectly or via a bridge group, and/or spiro-compounds. The polycycliccompounds may have, for example, from about 2 to about 4 rings. Therings may contain one or more heteroatoms (e.g., O, S or N). Typicallythe heterocyclic rings contain at least about 2 carbon atoms and no morethan about 2 heteroatoms, and generally only 1 heteroatom. Examples ofuseful strained ring compounds or groups include dioxolane, epoxide,oxetane and furan. Specific examples include cyclopropyl methanol,cyclobutyl amine, cyclobutyl hydroxyamine, 3,3-dimethyloxetane,1-methoxy-2-methylpropylene oxide, 2-methoxydioxolane and2,5-dimethoxytetrahydrofuran.

[0083] The nitro compounds may be aliphatic or aromatic. They maycontain one or more than one nitro group. The nitro compounds includepurely hydrocarbon and substituted hydrocarbon compounds. Examplesinclude nitromethane, nitropropane, dinitropropane, hydroxymethylnitropropane, 1,3-dimorpholino-2-nitropropane, 1,2-dinitropropane,2-methyl-2-nitropropane, bis(2-nitropropyl)methane, tetranitromethane,nitrobenzene, dinitrotoluene, trinitrotoluene, and nitrated phenols(e.g., butyl-dinitrophenol).

[0084] The hydroxyamines useful as combustion improvers may berepresented by the formulae

[0085] wherein each R is independently hydrogen or a hydrocarbyl group,R¹ is an alkylene group, and n is a number ranging from 1 to about 30.These types of hydroxyamines wherein the hydroxyl group is attacheddirectly to the nitrogen are also known as hydroxylamines. Each R may bea primary or secondary hydrocarbyl group. Each R group may contain from1 to about 25 carbon atoms, and in one embodiment 1 to about 8 carbonatoms. R¹ may be a lower alkylene group, and in one embodiment it isethylene or a propylene group. n may range from 1 to about 10, and inone embodiment 1 to about 5. Salts of these hydroxyamines may also beused. The salts include nitrates, sulfates, sulfonates, carbonates andcarboxylates. Examples of these hydroxyamines are disclosed in U.S. Pat.Nos. 3,491,151; 4,017,512; 5,731,462; 5,733,935; and 6,031,130, whichare incorporated herein by reference.

[0086] The concentration of the non-metallic combustion modifier in thewater blended fuel composition may range up to about 5% by weight, andin one embodiment about 0.005 to about 2% by weight.

[0087] Metallic Combustion Modifiers

[0088] The metallic combustion modifiers include fuel soluble metalliccompounds that enhance the burning characteristics of the fuel. Themetal may be Fe, Pt, Sr, Ce, Cu, Pd, Al, Ru or a combination of two ormore thereof. The fuel soluble compound may be in the form of aorganometallic complex or a coordination compound. Examples of suchcomplexes or coordination compounds include those disclosed in U.S. Pat.Nos. 4,891,050; 4,892,562; 5,034,020; 5,340,369; 5,344,467; 5,360,459;5,376,154; 5,501,714; 5,518,510; 5,534,039; 5,562,742; 5,593,464;5,693,106; 5,749,928; and 6,056,792. These patents are incorporatedherein by reference.

[0089] These complexes or coordination compounds may be added to thewater blended fuel composition at level sufficient to provide aconcentration of the metal in the range of up to about 200 parts permillion by weight (ppmw), and in one embodiment about 0.1 to about 200ppmw, and in one embodiment about 0.2 to 100 ppmw, and in one embodimentabout 0.5 to about 50 ppmw.

[0090] Water-Soluble Salt

[0091] The water blended fuel composition may contain one or morewater-soluble salts. These may be any material capable of formingpositive and negative ions in an aqueous solution that does notinterfere with the other additives or the hydrocarbon fuel. Theseinclude organic amine nitrates, azides, and nitro compounds. Alsoincluded are alkali and alkaline earth metal carbonates, sulfates,sulfides, sulfonates, and the like. Included are the amine or ammoniumsalts represented by the formula

k[G(NR₃)_(y)]^(y+)nX^(p−)

[0092] wherein G is hydrogen or an organic group of 1 to about 8 carbonatoms, and in one embodiment 1 to about 2 carbon atoms, having a valenceof y; each R independently is hydrogen or a hydrocarbyl group of 1 toabout 10 carbon atoms, and in one embodiment 1 to about 5 carbon atoms,and in one embodiment 1 to about 2 carbon atoms; X^(p−) is an anionhaving a valence of p; and k, y, n and p are independently integers ofat least 1. When G is H, y is 1. The sum of the positive charge ky⁺ isequal to the sum of the negative charge nX^(p−). In one embodiment, X isa nitrate ion; and in one embodiment it is an acetate ion. Examplesinclude ammonium nitrate, ammonium acetate, methylammonium nitrate,methylammonium acetate, ethylene diamine diacetate, urea nitrate, ureadinitrate, and mixtures of two or more thereof.

[0093] In one embodiment, the water-soluble salt functions as anemulsion stabilizer, i.e., it acts to stabilize the aqueous hydrocarbonfuel compositions.

[0094] In one embodiment, the water-soluble salt functions as acombustion improver. A combustion improver is characterized by itsability to increase the mass burning rate of the fuel composition. Thus,the presence of such combustion improvers has the effect of improvingthe power output of an engine.

[0095] The water-soluble salt may be present in the water blended fuelcomposition at a concentration of up to about 1% by weight, and in oneembodiment about 0.001 to about 1% by weight, and in one embodiment fromabout 0.01 to about 1% by weight.

[0096] Antifreeze Agent

[0097] In one embodiment, the water blended fuel composition contains anantifreeze agent. The antifreeze agent may be an alcohol or an ether.Examples include ethylene glycol, propylene glycol, methanol, ethanol,and mixtures thereof. The antifreeze agent is typically used at aconcentration sufficient to prevent freezing of the water used in thewater blended fuel composition. In one embodiment, the concentration isat a level of up to about 10% by weight, and in one embodiment about 1to about 5% by weight.

[0098] Other Fuel Additives

[0099] In addition to the foregoing, other fuel additives which are wellknown to those of skill in the art may be used. These include antiknockagents, lead scavengers, ashless dispersants, deposit preventers ormodifiers, dyes, antioxidants, rust inhibitors, corrosion inhibitors,bacteriostatic agents, gum inhibitors, metal deactivators, uppercylinder lubricants, biocides, and the like. These fuel additives may beused at concentrations that typically range up to about 1% by weight foreach additive based on the total weight of the water blended fuelcomposition, and in one embodiment about 0.01 to about 1% by weight.

[0100] Organic Solvent

[0101] The surfactant (iii), as well as other oil-soluble fuel additives(e.g., cetane improvers, dispersants, deposit preventers or modifiers,etc.), may be diluted with a substantially inert, normally liquidorganic solvent such as mineral oil, kerosene, diesel fuel, syntheticoil (e.g., ester of dicarboxylic acid), naphtha, alkylated (e.g.,C₁₀-C₁₃ alkyl) benzene, toluene or xylene to form an additiveconcentrate which is then mixed with the normally liquid hydrocarbonfuel and water. These concentrates generally contain from about 10% toabout 90% by weight of the foregoing solvent. The water blended fuelcomposition may contain up to about 10% by weight organic solvent, andin one embodiment about 0.01 to about 5% by weight.

[0102] Process for Forming the Water Blended Fuel Composition

[0103] The normally liquid hydrocarbon fuel, water, surfactant, andoptionally other ingredients as discussed above may be mixed underappropriate mixing conditions to form the desired water blended fuelcomposition. The mixing may involve high shear mixing, low shear mixing,or a combination thereof. The mixing may be conducted using a singlemixing step or multiple mixing steps. The mixing may be conducted on abatch basis, a continuous basis, or a combination thereof. The shearrate for the mixing may be up to about 500,000 sec⁻¹, and in oneembodiment about 20,000 to about 200,000 sec⁻¹, and in one embodimentabout 25,000 to about 120,000 sec⁻¹. The mixing may be conducted at atemperature in the range of about 0° C. to about 100° C., and in oneembodiment about 1° C. to about 50° C.

[0104] The Open-Flame Burning Apparatus

[0105] The open-flame burning apparatus may be any open-flame burningapparatus equipped to burn a liquid fuel. These include domestic,commercial and industrial burners. The industrial burners include thoserequiring preheating for proper handling and atomization of the fuel.Also included are oil fired combustion units, oil fired power plants,fired heaters and boilers, and boilers for use in ships including deepdraft vessels. The fuel burning apparatus may be a boiler for commercialapplications such as schools, hospitals, apartment buildings and otherlarge buildings. Included are boilers for power plants, utility plants,and large stationary and marine engines. The open-flame fuel burningapparatus may be an incinerator such as rotary kiln incinerator, liquidinjection kiln, fluidized bed kiln, cement kiln, and the like. Alsoincluded are steel and aluminum forging furnaces. The open-flame burningapparatus may be equipped with a flue gas recirculation system.

[0106] The Internal Combustion Engine

[0107] The internal combustion engine may be any internal combustionengine. These engines include spark-ignited (or gasoline) andcompression-ignited (or diesel) internal combustion engines, includingautomobile and truck engines, two-cycle engines, aviation pistonengines, marine and railroad diesel engines, and the like. Included areon and off-highway vehicle engines. The engine may be a turbine engine.The engine may be a homogeneous charge compression ignition engine(HCCI). The diesel engines include those for both mobile and stationarypower plants. The diesel engines include those used in urban buses, aswell as all classes of trucks. The diesel engines may be of thetwo-stroke per cycle or four-stroke per cycle type. The diesel enginesinclude heavy duty diesel engines.

EXAMPLE 1

[0108] The following water blended fuel formulations are prepared infive gallon quantities using a high shear mixer (all numerical valuesbeing in parts by weight): A B No. 2 fuel oil 87.17 77.17 Polyisobutene(Mn = 2300) substituted 1.90 1.90 succinic anhydride hydrolyzed withwater (21.5/0.44 anhydride to water weight ratio) to form thecorresponding acid, and diluted with oil (44.7 wt % diluent oil) Alkoxypoly ethoxylated alcohol 0.52 0.52 represented by formula RO(CH₂CH₂O)₈Hwhere R is C₉-C₁₁ Tartaric acid 0.41 0.41 Distilled water 10.00 20.00

[0109] The water blended fuel compositions for formulations A and B arewater-in-oil emulsions characterized by a continuous oil phase, and adiscontinuous aqueous phase. The discontinuous aqueous phase iscomprised of aqueous droplets having a mean diameter of 0.8 micron forformulation A, and 1.0 micron for formulation B.

[0110] The water blended fuel compositions for formulations A and Balong with a baseline control sample of the fuel oil used in theseformulations have the following properties: Formulation FormulationBaseline A B Percent Nitrogen (ASTM D 0.0250 0.0219 0.0223 4629) PercentSulfur (ASTM D 0.3274 0.1683 0.1121 2622) Specific gravity (ASTM D0.8567 0.8723 0.8840 4052) Viscosity @40° C., cSt 2.27 3.41 4.60 (ASTMD445-40) Flash Point, ° C. (ASTM 67 74 74 D93) Weight Percent Water0.050 7.96 18.61

[0111] The baseline fuel as well as formulations A and B are evaluatedin two different boilers using three different burners. The first boiler(Boiler No. 1) is a GO-3 conventional North American designthree-section, wet base, cast iron boiler. The second boiler (Boiler No.2) is a V83 conventional European design three-section, wet base, castiron boiler. The three burners are a standard burner, a high performanceburner and a low emissions burner. The fuel flow in each burner isadjusted to a heating rate of 140,000 BTU/hr. The flue gas has an O₂concentration of 3.0%, and a CO₂ concentration of 13.3%. The feed ratefor each fuel is as follows: Formulation Formulation Baseline A BRelative feed (gal/hr) 1.0 1.062 1.112 Percent flow increase — 6.3 11.2Net heating oil consumption 1.0 0.96 0.89 (gal/hr.)

[0112] The NO_(x) emissions for each burner are as follows for BoilerNo. 1: Formulation A Formulation B Base line NO_(x) % NO_(x) NO_(x)(ppm) (ppm) Reduction (ppm) % Reduction Standard 180 149 17.2 109 39.4Burner High 121 99 18.2 92 24.0 Performance Burner Low 72 68 5.6 61 15.3Emissions Burner

[0113] The NO_(x) emissions for each burner are as follows for BoilerNo. 2: Formulation A Formulation B Base line NO_(x) % NO_(x) NO_(x)(ppm) (ppm) Reduction (ppm) % Reduction Standard 162 136 16.0 106 34.6Burner High 120 108 10.0 100 16.7 Performance Burner Low 64 60 6.3 5120.3 Emissions Burner

[0114] While the invention has been explained in relation to specificembodiments, it is to be understood that various modifications thereofwill become apparent to those skilled in the art upon reading thespecification. Therefore, it is to be understood that the inventiondisclosed herein is intended to cover such modifications as fall withinthe scope of the appended claims.

1. A water blended fuel composition made by combining: (i) a normallyliquid hydrocarbon fuel; (ii) water; and (iii) a nitrogen-freesurfactant comprising: (iii)(a) a hydrocarbyl substituted carboxylicacid, or a reaction product of the hydrocarbyl substituted carboxylicacid or reactive equivalent of such acid with an alcohol, thehydrocarbyl substiuent of the acid or reactive equivalent containing atleast about 30 carbon atoms; and (iii)(b) at least one compoundrepresented by one or more of the formulae: RO(R′O)_(n)R′″  (iii-b-1)

RCOO(R′O)_(n)R′″  (iii-b-3)

wherein each R is independently hydrogen or a hydrocarbyl group of up toabout 60 carbon atoms; each R′ and R″ is independently an alkylene groupof 1 to about 20 carbon atoms; each R′″ is independently hydrogen, or anacyl or hydrocarbyl group of up to about 30 carbon atoms; n is a numberin the range of zero to about 50; and x, y and z are independentlynumbers in the range of zero to about 50 with the total for x, y and zbeing at least
 1. 2. The composition of claim 1 wherein the compositionfurther comprises an acid having a pKa of up to about
 6. 3. Thecomposition of claim 1 wherein the normally liquid hydrocarbon fuelcomprises a petroleum distillate fuel such as diesel fuel, gasoline,fuel oil or mixtures thereof; an alcohol; an ether; an ethanol; a fuelderived from a vegetable source; a biodegradable fuel; a biodiesel fuel;a fluid derived from a mineral source; a residual fuel; bitumen; aliquid fuel derived from corn, alfalfa, rapeseed, soybeans, shale, coal,or a mixture of two or more thereof; a fuel derived from aFischer-Tropsch synthesized hydrocarbon; or a mixture of two or morethereof.
 4. The composition of claim 1 wherein the composition furthercomprises a cetane improver, non-metallic combustion modifier, metalliccombustion modifier, water-soluble salt, antiknock agent, leadscavenger, ashless dispersant, deposit preventor or modifier, dye,antioxidant, rust inhibitor, corrosion inhibitor, bacteriostatic agent,gum inhibitor, metal deactivator, upper cylinder lubricant, antifreezeagent, biocide, organic solvent, or a mixture of two or more thereof. 5.The composition of claim 1 wherein the hydrocarbyl substituent for thesurfactant (iii)(a) is derived from polyisobutene, polypropylene,polyethylene, a copolymer derived from isobutene and butadiene, or acopolymer derived from isobutene and isoprene.
 6. The composition ofclaim 1 wherein the surfactant (iii)(a) comprises a polyisobutenesubstituted succinic acid.
 7. The composition of claim 1 wherein thesurfactant (iii)(a) comprises the reaction product of a polyisobutenesubstituted succinic acid or reactive equivalent thereof with analcohol.
 8. The composition of claim 1 wherein the surfactant (iii)(b)is represented by formula (iii-b-1) where R is a hydrocarbyl group ofabout 6 to about 30 carbon atoms, R′ is an alkylene group of about 2 toabout 4 carbon atoms, R′″ is hydrogen, and n is a number in the range of1 to about
 10. 9. The composition of claim 1 wherein the surfactant(iii)(b) is represented by formula (iii-b-1) wherein R is a hydrocarbylgroup of about 9 to about 11 carbon atoms, R′ is an alkylene group ofabout 2 carbon atoms, R′″ is hydrogen, and n is about
 8. 10. Thecomposition of claim 1 wherein the surfactant (iii)(b) is represented bythe formula (iii-b-1), wherein R is a hydrocarbyl group of about 14 toabout 30 carbon atoms, R′ is an alkylene group of about 2 carbon atoms,R′″ is hydrogen, and n is in the range of about 5 to about
 10. 11. Thecomposition of claim 1 wherein the compound represented by formula(iii-b-1) is C₉-C₁₁ alkoxy poly (ethoxy)₈ alcohol; C₁₂-C₁₅ alkoxy poly(isopropoxy)₂₂-₂₆ alcohol; oleyl alcohol pentaethoxylate, or a mixtureof two or more thereof.
 12. The composition of claim 1 wherein thecompound represented by formula (iii-b-2) is diglycerol monooleate,diglycerol monosteaate, polyglycerol monooleate, or a mixture of two ormore thereof.
 13. The composition of claim 1 wherein the compoundrepresented by formula (iii-b-3) is polyethylene glycol distearate,polyethylene glycol dioleate, polyethylene glycol soya bean oil ester,or a mixture of two or more thereof.
 14. The composition of claim 1wherein the compound represented by formula (iii-b-4) is glycerolmonooleate, diglycerol dioleate, diglycerol distearate, polyglyceroldioleate, or a mixture of two or more thereof.
 15. The composition ofclaim 1 wherein the compound represented by formula (iii-b-5) issorbitan monooleate, sorbitan monoisostearate, sorbitan sesquioleate,sorbitan trioleate, or a mixture of two or more thereof.
 16. Thecomposition of claim 1 wherein the compound represented by formula(iii-b-6) is polyethoxy glycerol trioleate.
 17. The composition of claim1 wherein the composition further comprises carboxylic acid, succinicacid, formic acid, acetylenedicarboxylic acid, benzenehexacarboxylicacid, benzenepentacarboxylic acid, benzenetetracarboxylic acid,benzenetricarboxylic acid, 2-butyn-1,4-dioic acid, 2-butynoic acid,citraconic acid, cyclopropane-1,1-dicarboxylic acid,2,6-dihydroxybenzoic acid, dihydroxymaleic acid, dihydroxymalic acid,dihydroxytatric acid, alpha, alpha-dimethyloxaloacetic acid,dipropylmalonic acid, ethylene oxide dicarboxylic acid, hydroxyasparticacid, maleic acid, 2-oxobutanoic acid, triethylsuccinic acid, citricacid, tartaric acid, glyoxalic acid, oxalic acid, lactic acid,oxomalonic acid, or a mixture of two or more thereof.
 18. Thecomposition of claim 1 wherein the composition further comprisestartaric acid.
 19. A combustion process comprising combusting the fuelcomposition of claim 1 in equipment selected from the group comprisingan open flame burner, engine and combination thereof.
 20. A waterblended fuel composition made by combining: a normally liquidhydrocarbon fuel; water; a polyisobutene -substituted succinic acidwherein the polyisobutene group has a number average molecular weight inthe range of about 750 to about 3000; and an alkoxy polyethoxy alcoholwherein the alkoxy group contains about 9 to about 11 carbon atoms andthe polyethoxy group contains about 8 ethoxy groups.
 21. A water blendedfuel composition made by combining: a normally liquid hydrocarbon fuel;water; a polyisobutene -substituted succinic acid wherein thepolyisobutene group has a number average molecular weight in the rangeof about 750 to about 3000; and an alkoxy polyethoxy alcohol wherein thealkoxy group contains about 14 to about 30 carbon atoms and thepolyethoxy group contains up to about 10 ethoxy groups.
 22. A method ofmaking a water blended fuel composition, comprising mixing at a shearrate of up to about 500,000 sec⁻¹: (i) a normally liquid hydrocarbonfuel; (ii) water; and (iii) a nitrogen-free surfactant comprising:(iii)(a) a hydrocarbyl substituted carboxylic acid, or a reactionproduct of the hydrocarbyl substituted carboxylic acid or reactiveequivalent of such acid with an alcohol, the hydrocarbyl substiuent ofthe acid or reactive equivalent containing at least about 30 carbonatoms; and (iii)(b) at least one compound represented by one or more ofthe formulae: RO(R′O)_(n)R′″  (iii-b-1)

RCOO(R′O)_(n)R′″  (iii-b-3)

wherein each R is independently hydrogen or a hydrocarbyl group of up toabout 60 carbon atoms; each R′ and R″ is independently an alkylene groupof 1 to about 20 carbon atoms; each R′″ is independently hydrogen, or anacyl or hydrocarbyl group of up to about 30 carbon atoms; n is a numberin the range of zero to about 50; and x, y and z are independentlynumbers in the range of zero to about 50 with the total for x, y and zbeing at least 1.